全文获取类型
收费全文 | 338篇 |
免费 | 27篇 |
专业分类
林业 | 23篇 |
农学 | 18篇 |
基础科学 | 2篇 |
83篇 | |
综合类 | 15篇 |
农作物 | 12篇 |
水产渔业 | 19篇 |
畜牧兽医 | 173篇 |
园艺 | 1篇 |
植物保护 | 19篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 14篇 |
2020年 | 6篇 |
2019年 | 16篇 |
2018年 | 10篇 |
2017年 | 16篇 |
2016年 | 15篇 |
2015年 | 18篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 26篇 |
2011年 | 28篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 25篇 |
2007年 | 21篇 |
2006年 | 16篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 3篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1975年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有365条查询结果,搜索用时 31 毫秒
101.
Domenico Caivano Antonello Bufalari Maria Elena Giorgi Maria Beatrice Conti Maria Chiara Marchesi Giovanni Angeli Francesco Porciello Francesco Birettoni 《Veterinary radiology & ultrasound》2014,55(5):561-564
A 3‐year‐old English Setter dog was presented for an acute onset of coughing. Tracheobronchoscopic examination allowed localization and removal of one grass awn foreign body. A second migrated grass awn was suspected to be present in the left caudal lung lobe. Transesophageal ultrasound revealed an area of pulmonary consolidation in the dorsomedial portion of left caudal lobe and a linear hyperechoic structure consistent with a grass awn foreign body within the area of consolidation. Transesophageal ultrasonography was also used to provide anatomical landmarks that facilitated successful thoracoscopic removal of the foreign body. 相似文献
102.
Valente EM Abou-Sleiman PM Caputo V Muqit MM Harvey K Gispert S Ali Z Del Turco D Bentivoglio AR Healy DG Albanese A Nussbaum R González-Maldonado R Deller T Salvi S Cortelli P Gilks WP Latchman DS Harvey RJ Dallapiccola B Auburger G Wood NW 《Science (New York, N.Y.)》2004,304(5674):1158-1160
Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. We previously mapped a locus for a rare familial form of PD to chromosome 1p36 (PARK6). Here we show that mutations in PINK1 (PTEN-induced kinase 1) are associated with PARK6. We have identified two homozygous mutations affecting the PINK1 kinase domain in three consanguineous PARK6 families: a truncating nonsense mutation and a missense mutation at a highly conserved amino acid. Cell culture studies suggest that PINK1 is mitochondrially located and may exert a protective effect on the cell that is abrogated by the mutations, resulting in increased susceptibility to cellular stress. These data provide a direct molecular link between mitochondria and the pathogenesis of PD. 相似文献
103.
van der Meijde M Marone F Giardini D van der Lee S 《Science (New York, N.Y.)》2003,300(5625):1556-1558
Water in the deep upper mantle can influence the properties of seismic discontinuities in the mantle transition zone. Observations of converted seismic waves provide evidence of a 20- to 35-kilometer-thick discontinuity near a depth of 410 kilometers, most likely explained by as much as 700 parts per million of water by weight. 相似文献
104.
Identification of a universal Group B streptococcus vaccine by multiple genome screen 总被引:2,自引:0,他引:2
Maione D Margarit I Rinaudo CD Masignani V Mora M Scarselli M Tettelin H Brettoni C Iacobini ET Rosini R D'Agostino N Miorin L Buccato S Mariani M Galli G Nogarotto R Nardi-Dei V Nardi Dei V Vegni F Fraser C Mancuso G Teti G Madoff LC Paoletti LC Rappuoli R Kasper DL Telford JL Grandi G 《Science (New York, N.Y.)》2005,309(5731):148-150
Group B Streptococcus (GBS) is a multiserotype bacterial pathogen representing a major cause of life-threatening infections in newborns. To develop a broadly protective vaccine, we analyzed the genome sequences of eight GBS isolates and cloned and tested 312 surface proteins as vaccines. Four proteins elicited protection in mice, and their combination proved highly protective against a large panel of strains, including all circulating serotypes. Protection also correlated with antigen accessibility on the bacterial surface and with the induction of opsonophagocytic antibodies. Multigenome analysis and screening described here represent a powerful strategy for identifying potential vaccine candidates against highly variable pathogens. 相似文献
105.
106.
107.
Summary
Vicia faba belongs to the sectionFaba. While the other species of the sectionV. narbonensis, V. johannis andV. bithynica cross enough well each other,V. faba seems to be strongly isolated from them. In addition the chromosome morphology ofV. faba differs from the other species of the section which among themselves are enough homogenous in this respect.To contribute to a wider knowledge on the taxonomical position ofV. faba in its section, electrophoretical and karyological analysis of 500 individuals belonging to 50 populations of different origin were carried out.The analyzed species were:V. faba, V. narbonensis, V. serratifolia, V. bithynica, V. galilaea andV. johannis.
Beitrag zur Taxonomie derVicia-Arten der SektionFaba
Zusammenfassung Vicia faba gehört zur sect.Faba. Während andere Arten der Sektion (V. narbonensis, V. johannis undV. bithynica) untereinander relativ gut kreuzbar sind, istV. faba von ihnen deutlich isoliert. Darüberhinaus unterscheidet sichV. faba in der Morphologie seiner Chromosomen von den anderen Arten der Sektion, die in dieser Hinsicht eine relativ einheitliche Merkmalsausprägung zeigen. Um zu einer besseren Kenntnis der systematischen Stellung vonV. faba innerhalb der Sektion beizutragen, wurden chromatographische und karyologische Analysen von 500 Individuen aus 50 Populationen verschiedener Herkunft durchgeführt. Analysiert wurdenV. faba, V. narbonensis, V. serratifolia, V. bithynica, V. galilaea undV. johannis.
Vicia, Faba
Vicia faba Faba. (V. narbonensis, V. johannis, V. bithynica) ,V. faba ë . ,V. faba , . V. faba , 500 50 . :V. faba, V. narbonensis, V. serratifolia, V. bithynica, V. galilaea, V. johannis.相似文献
108.
Bashar Qasim Mikael Motelica-Heino Sylvain Bourgerie Arnaud Gauthier Domenico Morabito 《Journal of Soils and Sediments》2016,16(3):811-820
Purpose
This study aimed at investigating the rhizosphere effects of Populus euramericana Dorskamp on the mobility of Zn, Pb and Cd in contaminated technosols from a former smelting site.Materials and methods
A rhizobox experiment was conducted with poplars, where the plant stem cuttings were grown in contaminated technosols for 2 months under glasshouse conditions. After plant growth, rhizosphere and bulk soil pore water (SPW) were sampled together. SPW properties such as pH, dissolved organic carbon (DOC) and total dissolved concentrations of Zn, Pb and Cd were determined. The concentrations of Zn, Pb and Cd in plant organs were also determined.Results and discussion
Rhizosphere SPW pH increased for all studied soils by 0.3 to 0.6 units compared to bulk soils. A significant increase was also observed for DOC concentrations regardless of the soil type or total metal concentrations, which might be attributed to the plant root activity. For all studied soils, the rhizosphere SPW metal concentrations decreased significantly after plant growth compared to bulk soils which might be attributed to the increase in pH and effects of root exudates. Zn, Pb and Cd accumulated in plant organs and the higher metal concentrations were found in plant roots compared to plant shoots.Conclusions
The restricted transfer of the studied metals to the plant shoots confirms the potential role of this species in the immobilization of these metals. Thus, P. euramericana Dorskamp can be used for phytostabilization of technosols.109.
Variation among and within Italian alfalfa ecotypes by means of bio-agronomic characters and amplified fragment length polymorphism analyses 总被引:1,自引:0,他引:1
Three accessions, corresponding to different ‘foundation’ farms, of each of the alfalfa (lucerne) Italian ecotypes ‘Vogherese’ and ‘Marem‐mano’, and two varieties were studied in order to evaluate: (1) the among‐ and within‐ecotype variation; and (2) the possibility of distinguishing the populations by means of bio‐agronomic characters and molecular markers (amplified fragment length polymorphisms, AFLPs). The two ecotypes could be distinguished by the differences in persistency after 15 cuttings in 3 years cultivation and by the seasonal distribution of the dry matter yield. Within‐ecotype variation was always of minor importance as compared with the among‐ecotype differences. The AFLP analyses generated 20 polymorphic fragments in ‘bulk’ samples: none was able to distinguish the two ecotypes, while variety‐specific fragments were found. The same analysis on an individual plant basis (485 polymorphic fragments) confirmed the absence of differences among ecotypes, while 10% of the total variance was attributable to variation among accessions within ecotype. The results of the analyses using agronomic traits and molecular markers are discussed in relation to the possibility of ecotype identification. 相似文献
110.
F. Pupilli S. Businelli F. Paolocci C. Scotti F. Damiani S. Arcioni 《Plant Breeding》1996,115(2):106-112
Seven widely-cultivated alfalfa varieties and three ecotypes adapted to Central Italy were used to evaluate the extent of polymorphism in that species. Twenty plants per accession were analysed with 16 RFLP probes combined with three restriction enzymes (48 probe/enzyme combination in total) and the data were used to compute the Nei's similarity index taken as a measure of inter- and intra-population RFLP variability. The varieties were, in general, more homogeneous than the ecotypes and the cultivars ‘Adriana’ and ‘Florida’ could be differentiated more easily than the others. Few accession-specific hybridizing fragments were scored and seven populations could be distinguished from the others on the basis of significant differences in the frequencies of specific fragments. The DNA of plant populations of several sizes was bulked and the ability to detect a given fragment in pooled samples was related to the fraction of plants having that fragment among the plants forming the bulk. The results are discussed with special emphasis on the practical utilization of RFLPs for varietal identification. 相似文献